As you are aware I have specified your luminaires and adaptations to older versions of some of them for thirty years. I have found your luminaires well designed, robust and basically fit for purpose which has been proven by their longevity of life. I have stated many times rather flippantly that "Coughtrie luminaires are the best things to have come out of Glasgow". I have no doubt that when the right scheme arises I will be specifying your products again.

London Borough of Hammersmith & Fulham

IK Ratings For Impact Resistant Luminaires: Everything You Need To Know

IK Equivalence

The IK rating is a vital tool for specifying luminaires especially in challenging environments. The IK rating was developed out of the old IP code which had a third digit to indicate impact resistance. 

The IK rating test is simple in principle; a weight of known value is dropped from a known height, to deliver an impact of a fixed energy, measured in joules. To achieve the IK rating a luminaire must survive a minimum of three identical impacts from test rigs such as pendulum, spring or dropped hammers.

Why is IK so important?

A broken luminaire is a hazard especially in public areas, either from debris or lack of required illumination. Damage entails additional costs to repair or replace quite apart from the potential need to close busy areas to access.

What IK do you need?

It depends on your risk assessment. In a low traffic area where there is little chance of damage, a rating of IK7 or below is likely to suffice. In areas where there is high traffic or risk of vandalism the top-rating of IK10 is recommended.

Is IK10 the best there is?

IK10 rating is the top of the official scale measured (IEC/BS EN 60598-1). The meaning of IK10++ is straightforward, in that the manufacturer has tested to exceed the standard but IK11 or more do not exist in the current regulations.